A module unit generally has a receiving element in the form of a trough-shaped carrier element, within which, as required, one or more circuit boards can be inserted in holding elements provided on the receiving element. The circuit boards are generally, in this case, surrounded in a U-shape by the holding elements in groove-shaped regions on two lateral regions of the circuit boards running in the direction of the longitudinal axis of the circuit boards. In order to prevent the circuit boards slipping out of the holding elements and therefore out of the receiving element, a lateral element is in each case screwed on the receiving element by means of screws at the two open lateral regions of the receiving element, via which the circuit boards can be inserted in the receiving element.
The drawback here is that, since to produce the module unit, the lateral elements have to be screwed to the receiving element, an additional manufacturing step and also additional fastening elements in the form of screws are necessary, so assembly of the module unit is complex and time-consuming.